Improvement in machines for making metal screws



C. M. SPENER.

f Machines for Making Meta! Srews NOZQE. Patenteld Feb.10,1874.

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"WIM 6556s. 717 fgiar UNITED STATES PATEN rre.

CHRISTOPHER M. SPENCER, OF HARTFORD, CONNECTICUT.

' IMPROVEMENT IN MACHINES FOR MAKING METAL SCREWS.

Specification forming part of Letters Patent No. 147,291, dated February l0, 1874; application tiled l December 17, 1873.

To all whom it may concern:

Be it known that I, CHRISTOPHER M. SPEN- CER, of Hartford, in the county of Hartford and State of Connecticut, have invented certainnew and useful Improvements in Machines for Making Screws, of which the following is a specification, reference being had to the accompanying drawings, where- Figure l is a front elevation of a machine embodying my said improvement. Fig. 2 is a top view of the same. Fig. 3 is a top view of the bed and ways -for the reciprocating tool-carriage. Fig. 4 is a bottom view of the tool-carriage.

The machine is more particularly intended for making metal or machine screws. The invention consists in an `arran gement for reversing the motion of the spindle through which therod off which the screws are made is fed; and in a combination of this arrangement with another arrangement for giving lnotion to the tool-carriage androtating the tool-bearing turret. i

The letter a indicates the base of the machine, having three standards, al a? a3, in which is hung the main shaft b, driven by appropriate power, and rotating in the direction indicated by the arrow overlying it in Fig. 2. On this shaft is the cam c, giving intermittent reciprocating motion to the slide cl, the nature and time of this reciprocation being indicated by the description of its purpose hereinafter contained. This slide has a tongue, d1, jutting into an annular groove in the drum c, which has a central spline fitting on the feather j" upon the shaft f, so that this drum must rotate with the shaft j', but is free to move lengthwise upon` it. On the shaft f are two loose pulleys, h and t', rotating in opposite directions, by means of belting, gearing, or friction. On the two sides of the drum c are clutch-pins c1 c2. On the sides of the two loose pulleys, next y the drum c, are clutch-pins h fi.

I'Vhen the drum is thrown against the pulley 7L, it is clutched thereto, and caused to revolve. When thrown against the pulley fi, it is clutched thereto, and made to revolve in the opposite direction, the rotation of the shaft f changing with the rotation 4of the drum e.

Through the longitudinal center of the shaft f the rod oft' which the screws are made is fed,

by means that are old and common, so far this present invention is concerned. `On the shaft b is another cam, g, giving reciprocating motion, by means of the tongue m, to the bed '12., moving on the ways o o. On this carriage n is set the turret p, which has a step-by-step y rotation given it by means of the circular ratchet r attached to the foot of the turret on the under side of the carriage n, and engaging with the pawl s, kept to place by the spring s. The turret is pierced with holes p, one or more, (in this case four,) to hold the tools for operating on the end of the rod.

Every time the carriage n moves back and away from the shaft f, the turret p makes one of its step rotations, and brings another tool into position for operation. One of these holes p holds the dies which cut the screw-thread upon the screw being made.` \Vhen the car-e riage n has moved this tool down toward the shaft f far enough to cut the desired length of thread, the cam `@reverses the motion of the shaft f, and thus permits the dies to run ott' the thread as the carriage n moves back. When the dies have been run olf the thread, the cam c again changes the rotation of the shaft f, as it was at iirst, and leaves it thus till the motion needs changing again to run theA dies off another thread.

The automatic reciprocation of the carriage ln, and the automatic rotation of the tool-bearing turret p, is shown, and intended to be claimed in other and previous Letters .Patent of mine; and it is only the combination of these parts with other parts that is claimed here-that is, so far as this one matter is conccrned.

With reference to the combination specified in the rst clause of the claim hereinafter con;1 tained, I would say that I am aware that de vices have hitherto been in use for reversing the motion of a rotating shaft. One is shown, for instance, in Letters Patent No. 129,806, dated July 23, 1872. In the device just referred to there are three pulleysupon the same shaft. The two outer ones are loose pulleys, and the middle one is fast on the shaft. A driving-belt runs upon each loose pulley, the two running in opposite directions. The belts are shifted by means of shippers actuated by cam-grooves made in the surface of a cylinder. One or the other of the driving-belts must be on the fixed pulley always and, when the belts are being shifted, the two belts will be both partly on the fixed pulley at the saine time, and Striving,` to turn it in different directions for, before one belt is Wholly oft' the fixed pulley, the other must be partly en. ln the device referred to, this makes no difference, as the shifting is done by hand; but, ina device which, like mine, is intended to be automatic, it Would be a Vfatal defect. Not only this, but in the device referred to there can be-no interregnum ofthe shifting` motion; While in my device sueh an interree'nuni is essential to give the cutting-tools time to operate. It Will be thus seen tha-t devices like that referred to will not fulfill the conditions required by my machine, Whieh *conditions my shifting,` device.

I claim as my invention- 1. The combination of the cam o, or its equivalent, slide d, clutch-drum e, made to rotate with the shaft f, but free to move upon it lengthwise, and the two clutelrpulleys hv i, de Signed to rotate in opposite directions, all con- Structed, arranged, and designed for operationand use substantially as shown and described. 2. The combination of the shaft b, eain c,

slide d, drum e, shaftj", clut/eh-pulleys h i, cani g, tongue m, bed o1, revolving tool-bearing' turret j), paivl s, and ratchet a', all constructed,

arranged, and designed for operation and use substantially as shown and described.

CHRISTOPHER M. SPENCER.

'Vitnesses:

WM. Enel/.iu SIMONDS, GEORGE L. ROGKWELL. 

